Genetics
Gregor Mendel
Father of Genetics
Trait
The different forms of a physical characteristic (ex: height, eye color, hair color, petal color, stem height)
Heredity
The passing on of traits from parent(s) to offspring.
Genetics
The study of Heredity.
Fertilization
The joining of sperm and egg.
Gene
The factor that controls a trait.
Allele
A letter used to represent a specific form of a gene.
Dominant Allele
A trait that always shows up (represented with a Capital letter).
Recessive Allele
A trait that is hidden when the dominant trait is present (represented with a lower case letter).
Probability
The percentage chance that something will occur.
Punnett Square
A chart used to represent genetic probability.
Phenotype
The physical appearance of traits (ex: green eyes, brown eyes, tall, short).
Genotype
The alleles (letters) used to represent a trait (ex: TT, Tt, tt). The genetic makeup
Homozygous
Two (2) identical alleles for a trait (ex: TT, tt).
Heterozygous
Two (2) different alleles for a trait (ex: Tt).
Codominance / Incomplete Dominance
When both alleles show up for a trait (ex: Red petal & White petal = Pink or Red/White petals).
Meiosis
Process where chromosomes in a cell are copied and reduced by half to create 4 sex cells (sperm or egg).
Mutation
Any change in a gene or chromosome that will change the makeup of what the trait would normally have been (ex: six-toed cats…the Hemingway cats).
Multiple Allele
Three or more forms of a gene that controls a trait (ex: blood type – A, B, O; Skin color, eye color).
Sex Chromosome
one (1) pair of chromosomes that determine whether something is a boy or a girl (XX = female, XY = male).
Sex-Linked Genes
Traits carried on sex chromosomes. Some traits can be passed on only by the father, and other traits can be passed on only by the mother. (ex: color blindness, baldness).
Carrier
A person who has one recessive allele for a trait and one dominant allele. This person does not show the trait, but can pass it on to their offspring.
Genetic Disorder
An abnormality in genetic inheritance.
Cystic Fibrosis
A congenital disorder (inherited at birth) causing mucous build up in lungs and other organs.
Sickle-cell disease
A congenital disorder (inherited at birth) where Blood cells form a sickle shape causing clotting in blood vessels.
Hemophilia
A congenital disorder (inherited at birth) causing difficulty in blood clotting.
Down Syndrome
A congenital disorder (inherited at birth) when a child is born with an extra copy of the 21st chromosome, typically causing physical abnormalities and health disorders.
Pedigree
A chart used to track traits within a family.
Karyotype
A picture of all the chromosomes within a cell. Used to diagnose genetic disorders.
Selective Breeding
Choosing organisms with desirable traits to breed and produce better offspring.
Inbreeding
Crossing two (2) parents with similar characteristics (2 plump turkeys to get plump offspring).
Hybridization
Crossing two genetically different parents to get desired offspring results (ex: Small McIntosh apple + Red Delicious apple = Empire apple).
Clone
An organism with exactly the same genes as a parent. (Typically engineered in a laboratory).
Genetic Engineering
Genes from one organism is transferred into the DNA of another organism. (Used to cure diseases and produce healthier crops, etc.).
Genome
All of the DNA sequence in one cell.
DNA Fingerprinting
Using DNA to show relationship in individuals.